Improved scroll for water-wheels



UNITED STATES PATENT OEEICE.

TIMOTHY ROSE, OF GORTLANDVILLE, NEW YORK.

IMPROVED SCROLL FOR WATER-WHEELS.

Specification forming part of Letters Patent No. 38,150, dated April 14, 1865i.

To all whom it may concern:

Be it known that I, TIMOTHY RosE, of the town of Oortlandville, in the county of Oortland and State of New York, have invented a new and useful Improvement in Scrolls or Water-Channels as Applied to W ater-Wheels; and I do hereby declare that the following is a full, clear, and exact description of the construction and operation of the same, reference being had to the annexed drawings, making a part of this specification, in which- Figure l is a perspective view, and Fig. 2 is a plan or horizontal section, like letters referring to like parts in each.

The object of my invention is to furnish a scroll or watervchannel to any turbine horizontal water-wheel, whether driven by the direct or reacting force of the water; and it consists in the peculiar construction and arrangement of the scroll, by means of which the water is controlled and made to act on the Wheel by direct action or reaction, and on a part of the buckets., or all of them, as dierent localities, heads, or amounts of water may demand.

A A represents a common form of wheel, with its shaft O. Upon the wheel is a flange and perpendicular rim, (represented by the dotted line,) and over which the scroll is titted and held in place by arms fastened to supports H H. The upper surface of the scroll B is spiral in form, regularly falling from its mouth or entrance P around its entire circumference. At the mouth the scroll is made about double the width of the buckets in the Wheel, and gradually narrowing back to the points I I, distant about one-third its circumference from its entrance, at which points it is of the same width ot' the buckets, and so continues round to near the point of beginning. This portion of the inner side of the scroll F between the points N and I represents an arc of a circle ot the same diameter as the inner circle of the buckets, but with a different center. The space over the wheel, and between the inner side of the buckets and the inner side of the scroll, is covered by a iioor or ange, E, forming a part of the scroll,and extending back to the point I. The area of the throat of the scroll being thus enlarged, water may pass in sufficient to supply the buckets beyond the enlargement.

D is a movable piece or plate, corresponding in shape and size to the side of the scroll, hinged thereto at the points I 1, with its front end curved so-as to pass through a perpendicular slot in the side of the scroll, and forming a false side thereto, back to the hinge. This false side may be moved in or out, working through the slot, increasing or diminishing the width and area of the throat at pleasure, a screw, M, or other device, holding it in the desired position.

O is a ap or trap gate, of which there may be one or more, hinged at Kto the under side of the coverV of the scroll, the other end being raised or lowered by a screw or otherwise in the top of the scroll. When down or shut, this gate is inclined toward the entrance of the scroll, so that the water may pass smoothly to the wheel, and lwhen up or open it lies against the top 0I the scroll.

The amount of water passing into the scroll and onto the wheel is gaged and controlled by the movable piece D. This might be done by a gate, but gates as usually made break the water, and its power beyond the gate is thus diminished. This movable gage-piece, on the contrary. not only controls or keeps back the Water as eifectually as a gate, but allows the water at all times to pass into the scroll in a constant, uniform, and unbroken volume, and the entrance to the scroll being large and gradually diminishing in size from its mouth, suiiicient water may be allowed to enter to keep the scroll full its entire circuit, and still the volume of water be unbroken. If the scroll, by means of the false side or movable piece, be set to vent, say, one hundred inches of water under a ten-foot head, and the water should rise in the tail-race three or four feet, from freshets or other cause, lessening the head by that amount, then the scroll may be enlarged by the false side, so as to vent two hundred inches or more, the issues of the wheel being capable of discharging that amount, or nearly so, thereby keeping up the same power on the wheel as before. rIhus the `same size and pattern of wheel and scroll may be used with varying heads, avoiding loss of power by back-water, and saving expense in multiplicity of patterns. Again, if with a given head the stop-gate be shut down and the gage-piece partially thrown back, the water coming only on three or four buckets, or if the gage-piece be open Wide and the stopgate up or open, in both these cases the buckets will be iiooded, and the Wheel driven by pressure or reaction so called; but if the.

gagepiece be set to the Width of the buckets and the stop-gate up, then the Wheel is driven by percussion or direct action, as the flow of water onto the Wheel is not sufcient to fill all its issues. 

